Although the FORWARD_IPV4 parameter of /etc/sysconfig/network disappeared in RHL 6.2 (now in /etc/sysctl.conf), it is still described in the manual. (I didn't chech whether /etc/sysctl.conf is described or not.) (Don't know if I selected the right package for this bug report.)
The Official Red Hat Linux Reference Guide no longer mentions use of the FORWARD_IPV4 value in /etc/sysconfig/network. Note that the bug was filed for the Installation Guide, but the originator of the bug wasn't sure of the package, which should have been rhl-rg.